检索结果-南通市图书馆

Nano-Micro Letters 2020年第8期12卷 46-59页

作者： Wenfu Xie Jianming li Yuke Song shijin li Jianbo li Mingfei Shao State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China Petroleum Geology Research and Laboratory Center Research Institute of Petroleum Exploration and Development(RIPED)PetroChinaBeijing 100083People’s Republic of China

Zinc-air batteries(ZABs)hold tremendous promise for clean and efficient energy storage with the merits of high theoretical energy density and environmental ***,the performance of practical ZABs is still unsatisfactory because of the inevitably decreased activity of electrocatalysts when assembly into a thick electrode with high mass ***,we report a hierarchical electrocatalyst based on carbon microtube@nanotube core-shell nanostructure(CMT@CNT),which demonstrates superior electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction with a small potential gap of 0.678 ***,when being employed as air-cathode in ZAB,the CMT@CNT presents an excellent performance with a high power density(160.6 mW cm^−2),specific capacity(781.7 mAhgZn^−1)as well as long cycle stability(117 h,351 cycles).Moreover,the ZAB performance of CMT@CNT is maintained well even under high mass loading(3 mg cm−2,three times as much as traditional usage),which could afford high power density and energy density for advanced electronic *** believe that this work is promising for the rational design of hierarchical structured electrocatalysts for advanced metal-air batteries.

关键词： Hierarchical structure Carbon microtube@nanotube Core–shell Zinc–air battery

Early Permian–Late Triassic Magmatism in the Tuotuohe Region of the Qinghai–Tibet Plateau: Constraints on the Tectonic evolution of the Western Segment of the Jinshajiang Suture

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2014年第2期88卷 498-516页

作者： QIAN Ye SUN Fengyue li Bile li shijin ZHAO Junwei College of Earth Sciences Jilin University Qinghai Geological Survey No.5 Geological and Mineral Survey Institute of Qinghai Province

In this paper we present new zircon U-Pb ages,whole-rock major and trace element analyses,and zircon Hf isotopic data for magmatic rocks in the Tuotuohe region of the western segment of the Jinshajiang *** aim is to constrain the Early Permian-Late Triassic tectonic evolution of the *** from the magmatic rocks of the Tuotuohe region are euhedralsubhedral in shape and display fine-scale oscillatory zoning as well as high Th/U ratios （0.4-4.6）,indicating a magmatic *** zircon U-Pb ages obtained using LA-ICP-MS are 281 ± 1 Ma,258 ± 1 Ma,244 ± 1 Ma,and 216 ± 1 Ma,which indicate magmatism in the Early Permian-Late Triassic.A diorite from Bashihubei （BSHN） has SiO2 =57.18-59.97 wt％,Al2O3=15.70-16.53 wt％,and total alkalis （Na2O ＋ K2O） =4.46-6.34 wt％,typical of calc-alkaline and metaluminous series.A gabbro from Bashibadaoban （BSBDB） belongs to the alkaline series,and is poor in SiO2 （45.46-54.03 wt％） but rich in Al2O3 （16.19-17.39 wt％） and total alkalis （Na2O ＋ K2O =5.48-6.26 wt％）.The BSHN diorite and the BSBDB gabbro both display an enrichment of LREEs and liLEs and depletion of HFSEs,and they have no obvious Eu anomaly; they have relatively low MgO contents （2.54-4.93 wt％）,Mg# values of 43 to 52,and low Cr and Ni contents （8.07-33.6 ppm and 4.41-14.2 ppm,respectively）,indicating they differentiated from primitive mantle *** have low Nb/U,Ta/ U,and Ce/Pb ratios （1.3-9.6,0.2-0.8,and 0.1-18.1,respectively）,and their initial Hf isotopic ratios range from ＋9.6 to ＋16.9 （BSHN diorite） and ＋6.5 to ＋12.6 （BSBDB gabbro）,suggesting their primary magmas were derived mainly from the partial melting of a mantle wedge that had been metasomatized by subduction *** all the new data together,we conclude that the western and eastern segment of the Jinshajiang suture regions underwent identical processes of evolution in the Early Permian-Late Triassic：oceanic crust subduction before the Early Permian,continental collision during the Early-Middle T

关键词： zircon U-Pb chronology zircon Hf isotopes geochemistry tectonic setting Tuotuohe region Jinshajiang suture Qinghai-Tibet Plateau

Frequency Domain Filtering SAR Interferometric Phase Noise Using the Amended Matrix Pencil Model

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2019年第5期119卷 349-363页

作者： Yandong Gao Shubi Zhang Kefei Zhang shijin li School of Environment Science and Spatial Informatics China University of Miningand TechnologyXuzhou221116China SPACE Research Centre School of Mathematical and Geospatial SciencesRMIT UniversityMelbourneVictoria3000Australia

Interferometric phase filtering is one of the key steps in interferometricsynthetic aperture radar (InSAR/SAR). However, the ideal filtering results are difficult toobtain due to dense fringe and low coherence regions. Moreover, the InSAR/SAR datarange is relatively large, so the efficiency of interferential phase filtering is one of themajor problems. In this letter, we proposed an interferometric phase filtering methodbased on an amended matrix pencil and linear window mean filter. The combination ofthe matrix pencil and the linear mean filter are introduced to the interferometric phasefiltering for the first time. First, the interferometric signal is analyzed, and theinterferometric phase filtering is transformed into a local frequency estimation ***, the local frequency is estimated using an amended matrix pencil at a window. Thelocal frequency can represent terrain changes, thus suggesting that the frequency can beaccurately estimated even in dense fringe regions. Finally, the local frequency is filteredby using a linear window mean filter, and the filtered phase is recovered. The proposedmethod is calculated by some matrices. Therefore, the computational complexity isreduced, and the efficiency of the interferometric phase filtering is *** are conducted with simulated and real InSAR data. The proposed methodexhibits a better filtering effect and an ideal efficiency as compared with the traditionalfiltering method.

关键词： Interferometric phase filtering interferometric synthetic aperture radar local frequency estimation amended matrix pencil linear window mean filter

Integrated Nanostructural Electrodes Based on Layered Double Hydroxides

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2019年第3期2卷 158-171页

作者： Wenfu Xie Yuke Song shijin li Mingfei Shao Min Wei State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Layered double hydroxides(LDHs), as a class of typical two-dimensional materials, have sparked increasing interest in the field of energy storage and conversion. In the last few years, the research about LDHs as electrode active materials has seen much progress in terms of structure designing, material synthesis, properties tailoring, and applications. In this review, we focus on the integrated nanostructural electrodes(INEs) construction using LDH materials, including pristine LDH-INEs, hybrid LDH-INEs, and LDH derivativeINEs, as well as the performance advantages and applications of ***, in the final section, the insights about challenges and prospective in this promising research field were concluded, especially in regulation of intrinsic activity and uncovering of structure–activity relationship, which would push forward the development of this fast-growing field.

关键词： electrochemical redox reaction electrode design energy storage and conversion Integrated nanostructural electrodes layered double hydroxides

Air flow exploration of abrasive feed tube

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2009年第6期25卷 761-768页

作者： shijin Zhang Xiaohong li Yilei Gu College of Resources and Environmental Science,Chongqing University, 400044 Chongqing, China College of Resources and Environmental Science Chongqing University 400044 Chongqing China

An abrasive water-jet cutting process is one in which water pressure is raised to a very high pressure and forced through a very small orifice to form a very thin high speed jet beam. This thin jet beam is then directed through a chamber and then fed into a secondary nozzle, or mixing tube. During this process, a vacuum is generated in the cham- ber, and garnet abrasives and air are pulled into the chamber, through an abrasive feed tube, and mixes with this high speed stream of water. Because of the restrictions introduced by the abrasive feed tube geometry, a vacuum gradient is generated along the tube. Although this phenomenon has been recog- nized and utilized as a way to monitor nozzle condition and abrasive flowing conditions, yet, until now, conditions inside the abrasive feed line have not been completely understood. A possible reason is that conditions inside the abrasive feed line are complicated. Not only compressible flow but also multi- phase, multi-component flow has been involved in inside of abrasive feed tube. This paper explored various aspects of the vacuum creation process in both the mixing chamber and the abrasive feed tube. Based on an experimental exploration, an analytical framework is presented to allow theoretical calculations of vacuum conditions in the abrasive feed tube.

关键词： Abrasive feed tube- Water jet cutting. Vacuum gradient

Geochronology, Geochemistry and Sr-Nd-Pb-Hf Isotopes of No. I Complex from the Shitoukengde Ni–Cu Sulfide Deposit in the Eastern Kunlun Orogen, Western China: Implications for the Magmatic Source, Geodynamic Setting and Genesis

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第1期92卷 106-126页

作者： li liang SUN Fengyue li Bile li shijin CHEN Guangjun WANG Wei YAN Jiaming ZHAO Tuofei DONG Jun ZHANG Dexin College of Earth Sciences Jilin University Changchun 130061 China Qinghai Bureau of Geological Survey Xining 810001 China No. 108 Geological Party Sichuan Bureau of Geology and Mineral Exploration Chengdu 611230 China

The Shitoukengde Ni-Cu deposit, located in the Eastern Kunlun Orogen, comprises three mafic-ultramafic complexes, with the No. I complex hosting six Ni-Cu orebodies found recently. The deposit is hosted in the small ultramafic bodies intruding Proterozoic metamorphic rocks. Complexes at Shitoukengde contain all kinds of mafic-ultramafic rocks, and olivine websterite and pyroxene peridotite are the most important Ni-Cu-hosted rocks. Zircon U-Pb dating suggests that the Shitoukengde Ni-Cu deposit formed in late Silurian （426-422 Ma）, and their zircons have ~Hf（t） values of-9.4 to 5.9 with the older TDMm ages （0.80-1.42 Ga）. Mafic-ultramafic rocks from the No. I complex show the similar rare earth and trace element patterns, which are enriched in light rare earth elements and large ion iithophile elements （e.g., K, Rb, Th） and depleted in heavy rare earth elements and high field strength elements （e.g., Ta, Nb, Zr, Ti）. Sulfides from the deposit have the slightly higher ~34S values of 1.9-4.3%o than the mantle （0 ~ 2%o）. The major and trace element characteristics, and Sr-Nd-Pb and Hf, S isotopes indicate that their parental magmas originated from a metasomatised, asthenospheric mantle source which had previously been modified by subduction-related fluids, and experienced significant crustal contamination both in the magma chamber and during ascent triggering S oversaturation by addition of S and Si, that resulted in the deposition and enrichment of sulfides. Combined with the tectonic evolution, we suggest that the Shitoukengde Ni-Cu deposit formed in the post-collisional, extensional regime related to the subducted oceanic slab break-off after the Wanbaogou oceanic basalt plateau collaged northward to the Qaidam Block in late Silurian.

关键词： Sr-Nd-Pb-Hf isotopes crustal contamination oceanic slab break-off post-collisionalextension Shitoukengde Ni-Cu deposit Eastern Kunlun Orogen